Weird Bug When Trying To Mirror Keyframes
What is your goal here? What do you want to achieve by mirroring keyframes? I'm assuming, that you're trying to mirror pose and make a keyframe of it.Is that right? If so your armature probably is not symmetrized. It means, that symmetric bones on both sides of the body don't have symmetrical rolls. What you need to do is go in edit mode, select all bones of legs and arms, press W and choose Symmetrize. After that mirroring pose should work perfectly.